Plant Industries and Climatic Plant Formations 345 



In spite of these exceptions to the rule, it is generally true that 

 the great climatic plant formations are each characterized by 

 certain groups of plant products and plant industries. In the 

 following paragraphs the more important products and indus- 

 tries of each of the natural divisions of the vegetation of North 

 America are discussed. 



The tundra. This inhospitable region, lying far to the north, 

 has few inhabitants except the Eskimos along the northern 

 coasts. They derive most of their food from the seals and shore 

 birds, though they do invade the tundra on hunting expeditions 

 for caribou, musk oxen, and smaller animals. 



Here more than anywhere else on the continent the vegetation 

 of the sea is important to men. On this vegetation, especially 

 the microscopic plants, the fish are dependent, and they in turn 

 are fed on by seals, walrus, and shore birds — the primary food 

 of the inhabitants. On land the lichens, grasses, and other plants 

 furnish the food of the arctic hares, caribou, and musk oxen — 

 the secondary food of the Eskimos. Direct use of plants is very 

 limited, and plant industries are entirely wanting. 



The northern evergreen forest. The excellent quality of the 

 wood that is derived from the white pine, spruce, red pine, and 

 arbor vitae, and its value for building houses and ships, led to 

 the early invasion of the forests of Canada, New England, and 

 the Great Lakes region by lumbermen ; and until 1900 the north- 

 ern evergreen forest was the most important center of lumber 

 production. 



During the past 30 years the spruce has become a valuable 

 wood for the production of paper pulp. Its freedom from resin, 

 its white color, and its soft, smooth, and uniform grain make it 

 the best source of white book and print paper. Hemlock is 

 second in importance in the making- of pulp for newspaper, wrap- 

 ping paper, and other cheap grades of paper. Consequently, at 

 the present time the paper-pulp industry centers in the north- 

 ern forest. 



